Adaptive Signal Processing Techniques for Robust, High Capacity Spread-Spectrum Multiple Access

Abstract

This project is concerned with signal processing and coding techniques that can improve the performance of spread-spectrum, multiple-access systems. Specific topics investigated during the course of this project include the following: (1) reduced-rank interference suppression; (2) combined coding and interference suppression (3) joint transmitter-receiver optimization in the presence of multiple-access interference; and (4) the effect of limited feedback on the performance of joint transmitter-receiver optimization schemes. The theory of large random matrices was used to analyze the performance of both interference suppression and interference avoidance schemes. For example, the authors have used these techniques to analyze the performance of adaptive reduced- and full-rank least squares filtering for interference suppression with limited training. This analysis shows the effects of algorithm parameters, which determine the initialization and data windowing, along with system load and noise level. Other contributions include optimization of the ratio of pilot-to-data power and code rate with adaptive linear interference suppression, and signature optimization for combined interference avoidance and pre-equalization of multi-path. Transmitter optimization with limited feedback also has been considered, and bounds on the achievable performance as a function of feedback bits per dimension have been obtained. This project has resulted in a patent application for an adaptive reduced-rank filter, a paper award (for work on reduced-rank filtering), and numerous journal and conference publications on the preceding topics. A list of 34 journal articles, papers in review, and conference papers is included.

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Document Details

Document Type
Technical Report
Publication Date
Sep 02, 2003
Accession Number
ADA429223

Entities

People

  • Michael L. Honig

Organizations

  • Northwestern University

Tags

Communities of Interest

  • Human Systems

DTIC Thesaurus Topics

  • Adaptive Filters
  • Algorithms
  • Coding
  • Feedback
  • Filters
  • Filtration
  • Information Science
  • Information Theory
  • Multiple Access
  • Patent Applications
  • Patents
  • Signal Processing
  • Spectra
  • Spread Spectrum
  • Training
  • Transmitters
  • Wireless Communications

Fields of Study

  • Engineering

Readers

  • Adaptive Control and Estimation with Uncertainty in Dynamic Systems.
  • Radio communications and signal processing.
  • Technical Research and Report Writing.